<?php
$video = (int)$_GET["v"];
if($video == 1){
?>
<iframe width="560" height="315" src="http://www.youtube.com/embed/gUHC3LLiGZU?autoplay=1" frameborder="0" allowfullscreen></iframe>

<?php }else if($video == 2){ ?>

<iframe width="560" height="315" src="http://www.youtube.com/embed/MU2zneObjJA?autoplay=1" frameborder="0" allowfullscreen></iframe>

<?php }else{?>

<iframe width="560" height="315" src="http://www.youtube.com/embed/QmJczE6REc0?autoplay=1" frameborder="0" allowfullscreen></iframe>
<?php } ?>